Multiply, reduce to lowest terms, and write as a mixed number: $ 2\dfrac{4}{5} \times 5\dfrac{4}{5} $
$ = \dfrac{14}{5} \times \dfrac{29}{5}$ $ = \dfrac{14 \times 29}{5 \times 5}$ $ = \dfrac{406}{25}$ $ = 16 \dfrac{6}{25}$